Validation of a Rapid and Sensitive Liquid Chromatography–Tandem Mass Spectrometry Method for Free and Total Mycophenolic Acid
Open Access
- 1 January 2004
- journal article
- research article
- Published by Oxford University Press (OUP) in Clinical Chemistry
- Vol. 50 (1), 152-159
- https://doi.org/10.1373/clinchem.2003.024323
Abstract
Background: Because mycophenolic acid (MPA) is highly protein bound and because the free fraction is the pharmacologically active portion, a rapid, reliable, and sensitive procedure is required to study the relationship between free MPA and treatment efficacy/toxicity. Liquid chromatography–tandem mass spectrometry is ideally suited for such a method. Methods: Free MPA was isolated from plasma by ultrafiltration. An online extraction cartridge with a column-switching technique, analytical liquid chromatography over an Aqua Perfect C18 column, and electrospray tandem mass spectrometry was used to quantify free and total MPA. To investigate ion suppression, a continuous infusion of MPA was introduced into the effluent from the HPLC column, and different ultrafiltrates and extracted plasma samples were injected on the column. Results: A chromatographic run time of 4 min separated MPA from metabolites and internal standard, thereby avoiding interference from in-source fragmentation. Ion suppression occurred well before elution of MPA and internal standard. The lower limit of quantification for free MPA was 0.5 μg/L, and the method was linear to 1000 μg/L. Interassay imprecision (CV) was <10% for free MPA (0.5–333 μg/L). Agreement was good for free MPA (n = 52) and total MPA (n = 106) between the proposed method and a validated HPLC method with ultraviolet detection. The Passing–Bablok regression line was: y = 0.95x + 0.27 μg/L for free MPA and y = 0.98x + 0.03 mg/L for total MPA. Conclusions: The presented method allows the accurate, precise, and rapid determination of free and total MPA in plasma over a wide analytical range covering the concentrations relevant to pharmacokinetic studies and routine monitoring of this drug.Keywords
This publication has 15 references indexed in Scilit:
- The Pharmacokinetic-Pharmacodynamic Relationship for Total and Free Mycophenolic Acid in Pediatric Renal Transplant RecipientsJournal of the American Society of Nephrology, 2002
- Mechanistic investigation of ionization suppression in electrospray ionizationJournal of the American Society for Mass Spectrometry, 2000
- Quantification of free mycophenolic acid by high-performance liquid chromatography–atmospheric pressure chemical ionisation tandem mass spectrometryJournal of Chromatography B: Biomedical Sciences and Applications, 2000
- Pharmacokinetics and Concentration-Control Investigations of Mycophenolic Acid in Adults After TransplantationTherapeutic Drug Monitoring, 2000
- Pharmacokinetic and Metabolic Investigations of Mycophenolic Acid in Pediatric Patients After Renal Transplantation: Implications for Therapeutic Drug MonitoringTherapeutic Drug Monitoring, 2000
- The Effect of Renal Insufficiency on Mycophenolic Acid Protein BindingThe Journal of Clinical Pharmacology, 1999
- A RANDOMIZED DOUBLE-BLIND, MULTICENTER PLASMA CONCENTRATION CONTROLLED STUDY OF THE SAFETY AND EFFICACY OF ORAL MYCOPHENOLATE MOFETIL FOR THE PREVENTION OF ACUTE REJECTION AFTER KIDNEY TRANSPLANTATION1Transplantation, 1999
- The pharmacokinetic-pharmacodynamic relationship for mycophenolate mofetil in renal transplantation*Clinical Pharmacology & Therapeutics, 1998
- DECREASED PROTEIN BINDING OF MYCOPHENOLIC ACID ASSOCIATED WITH LEUKOPENIA IN A PANCREAS TRANSPLANT RECIPIENT WITH RENAL FAILURETransplantation, 1998
- Matrix Effect in Quantitative LC/MS/MS Analyses of Biological Fluids: A Method for Determination of Finasteride in Human Plasma at Picogram Per Milliliter ConcentrationsAnalytical Chemistry, 1998